Adhesion of heat-inactivated Bifidobacterium adolescentis DM8504 to human colorectal carcinoma CCL-229 cells

摘要

Bifidobacterium adolescentis DM8504 and CCL-229 cell line were used as the representative of bifidobacteria and well-characterized cellular model, respectively. The heat-inactivated B. adolescentis DM8504 was able to adhere to the human colorectal carcinoma cell line CCL-229. We determined the factors involved which mediates the adhesion properties of heat-inactivated bifidobacteria. CCL-229 cells were treated with heat-inactivated or live strain bifidobacteria. All suspensions were added to each well of the tissue culture plate, and the plate was incubated at 37°C for 1 h. Adhesion of heat-inactivated bifidobacteria to the intestinal cell surfaces is quantitated and characterized by microscopic examination. The supernatant derived from culture contained factors which contribute to bacterial adhesion. The proteinaceous component of the supernatant did not possess any adhesion promoting activity. Bacterial adhesion was increased after addition of 10% inactivated fetal bovine serum. These results showed that the heat-inactivated B. adolescentis DM8504 exhibits similar ability to adhere to CCL-229 cells than live bifidobacteria. This adhesion is mediated by factors found in spent culture supernatant. Furthermore, this factor is not modified by trypsin pretreatment of the supernatant.